Silicon nitride (SiN(x)) and parylene thin films were deposited onto flexible polyimide (PI) substrates using plasma-enhanced chemical vapor deposition and a parylene reactor for transparent barrier applications. The PI substrates from the Industry Technology Research Institute with high optical transmittance and high glass transition temperature were used. A relatively high growth temperature of 200 degrees C was chosen to deposit the SiN(x) films. To characterize the SiN(x) films deposited under different growth temperatures, a wet-etching process was performed to visualize the defect distribution in the barrier films. After 120 min of etching, the etching area ratio decreased from 44.9 to 6.7%, while the average defect spacing increased from 125 to 450 mu m with increasing growth temperature. Under room temperature and relative humidity of 50%, four SiN(x)/parylene stacks with the SiN(x) films deposited at 80 and 200 degrees C were demonstrated to decrease the water vapor transmission rate to 7.9x10(-4) and 7.41x10(-6) g/m(2)/day, respectively. As a result, ultralow permeation can be achieved with less repeating barrier stacks by using high temperature deposited SiN(x) films in the barrier structures

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